The present invention relates generally to suppressing the re-broadcast of redundant messages in a vehicular ad hoc network.
Multi-hop geocast protocols provide for the periodic broadcasting of vehicle driving awareness conditions such as slow moving vehicles (SVA) and post crash notification (PCN). Vehicles disseminate messages conditions containing warning information to other vehicles within a broadcasting range for notification of the various driving conditions. The objective of message dissemination is to reduce accidents by forewarning vehicle drivers of such conditions. When a vehicle receives a notification message, the receiving vehicle attempts to re-broadcast the message to other vehicles within its broadcasting range for alerting other vehicles of the existing condition.
The drawback with the above described system is the flooding of messages (e.g., broadcast storm) within the network. When the majority of the vehicles within a broadcast range attempt to re-broadcast messages, the wireless channel becomes overloaded, resulting in packet collision. The result of such an overload is performance degradation with respect to communication reliability.